Did the national dietary guidelines overreach when they recommended cutting dietary fat consumption to less than 30% and saturated-fat intake to less than 10% of daily energy intake? A new review suggests they did, with investigators reporting that not a single randomized, controlled clinical trial backed the advice when the recommendations were issued in 1977 in the US and in 1983 in the UK.
Given the absence of evidence, the investigators say their review concludes that the present dietary advice, which currently recommends Americans keep saturated fat to 5% to 6% of daily calories, needs more than an overhaul. In fact, they believe the dietary fat recommendations should never have been introduced in the first place.
“When you tell people to lower saturated fat—protein typically stays the same, we get about 15% to 20% of our calories from protein—they inherently increase the consumption of unsaturated fats, particularly the omega-6 fats found in vegetable oils, and carbohydrates,” senior investigator Dr James DiNicolantonio (St Luke’s Mid America Heart Institute, Kansas City, MO) told heartwire . Such a substitution, he said, ends up doing more harm than good.